1. Field of the Invention
The present invention relates to a pouring mechanism for controllable flow especially, but not exclusively, adapted for application to lids employed with containers for base colors used in automobile factories and which are used in mixing machines.
2. Description of the Prior Art
At the present time, in pouring mechanisms of this general type, regulation of the flow is obtained by means of two principal types of valves, i.e., a valve of the "guillotine" type and a mechanism of the "clapper" type.
Guillotine type valves generally incorporate a valve element such as a closure slidably mounted over the face of the spout of the dispenser, upon which it is maintained in close-fitting contact, for example, by means of a plate-spring. This valve is caused to close (position in which it closes off the entire cross section of the pourer spout) by means of a close-coil spring and can be caused to open by means of a lever whose movement is opposed to that of said spring. To proceed with pouring or dispensing, the operator acts upon the control lever in such a way as to cause withdrawal of the valve which results in an opening whose more or less small size is a function of the position of the lever. In the case where the front of the pourer is in the shape of a dihedral neck, it is possible to obtain very exact dispensing because the triangular opening thus obtained can be sufficiently small to obtain a dropwise delivery.
On the contrary, at full opening, the freed surface is not very large so that the maximum flow of such a pouring mechanism is relatively limited.
Another drawback to this type of valve resides in the fact that it is difficult to economically achieve a good fluid-tight fit between the spout and its seating taking into account the length of the spout and its control mechanism. Furthermore, these pouring mechanisms are particularly prone to clogging.
Clapper valves use a valve element or a rocker valve, jointed upon the rear border of the pouring mechanism and furnished with an operating lever. The arrangement of this valve is such that, at rest, the valve element is maintained in fluid-tight contact upon the edge of the pouring mechanism, for example, by the action of a spring. On the other hand if an action is exerted on the lever opposed to that of the spring, a rocking towards the top of the valve is brought about and, consequently, a sectional opening increasing towards the front end of the neck, which makes a sampling possible.
This system makes it possible, therefore, to provide a relatively large opening permitting a considerable flow and a good visibility inside the tank in order to monitor the flow rate of the liquid. On the other hand, the accuracy of the dispensing which is a function of the tank's angle, depends consequently much more on the skill of the operator than in the previously described example.
In addition, this type of valve permits the instantaneous stopping of the flow through closure of the clapper, but excludes a dropwise flow, taking into account the perimeter of the neck.